FWIW, I have the opposite experience with online versus offline.

I avoid "rationalists" in meatspace because there's pressure to justify my preferences in terms of a higher-level explicit utility function before they can be considered valid.

It wouldn't surprise me at all to see this on the website, but I wouldn't expect it to happen in meatspace.

(Obviously meetups vary, but I help organize the London meetup, I went to the European megameetup, I went to CFAR, and I've spent a small amount of time with the SF/Berkeley crowd.)